Dear all, Are there any documents or examples about SAR interferometry with OTB?
I am a researcher on SAR interferometry algorithms for over ten years and I am very excited to hear that OTB can do the job like ISCE or GAMMA etc. But I found it is hard to start as SAR interferometry is quite a long chain of algorithms to follow and the The configure files of diapOTB python scripts are not documented well. I believe someone has suceeded in SAR interferometry with OTB but the topic is seldom discussed here. Can someone kindly give me some advice?
I don’t know about interferometry, but I can help with DEM.
In OTB applications, the DEM path must be a directory that contains rasters. You can put your .hgt files in this directory. I believe that since OTB 5 or 6, other raster formats are also supported as DEM (e.g. GeoTiff, …).
Also, you can take a look to the DowloadSRTMTiles application that will automatically download the SRTM tiles for you!
Thanks for your reply Rémi!
But when I read the source code below to deal with the input hgt file, I think the “DEM.hgt” metioned above is not just a hgt file that downloaded with the DowloadSRTMTiles.
def getDEMInformation(dem):
"""
Retrieve DEM information thanks to ReadImageInfo
"""
# Get information about DEM (spacing, size ..)
ReadDEMInfo = otb.Registry.CreateApplication("ReadImageInfo")
ReadDEMInfo.SetParameterString("in", dem)
ReadDEMInfo.SetParameterString("keywordlist", "true")
ReadDEMInfo.Execute()
dictDEMInformation = {}
dictDEMInformation['spacingXDEM'] = ReadDEMInfo.GetParameterFloat("spacingx")
dictDEMInformation['estimatedGroundSpacingXDEM'] = ReadDEMInfo.GetParameterFloat("estimatedgroundspacingx")
dictDEMInformation['spacingYDEM'] = ReadDEMInfo.GetParameterFloat("spacingy")
dictDEMInformation['estimatedGroundSpacingYDEM'] = ReadDEMInfo.GetParameterFloat("estimatedgroundspacingy")
return dictDEMInformation
The keywords above such as “spacingx” were not metioned before, There must be a auxilliary file with it.
I can’t really help you on interferometry but you can have a look at the documentation of the diapotb module if you haven’t found it already. The doc is a bit light, but this page might help you.
Thank you very much for your help, Cédric.
I have read the documentation already and it is really helpful to establish a general view of the DIapOTB. SAR interferometry is quite a long chain of algorithms to follow and preparations for the inputs are not mentioned there. I think examples might be more useful for a starter.